Independent mobility is critical to individuals of any age. While the needs of many individuals with disabilities can be satisfied with power wheelchairs, some members of the disabled community find it difficult or impossible to operate a standard power wheelchair. This population includes, but is not limited to, individuals with low vision, visual field neglect, spasticity, tremors, or cognitive deficits. The goal of this project is to develop a set of components that can be added to standard power wheelchairs to convert them into "smart" wheelchairs which can assist the user in navigation and obstacle avoidance. During Phase I, a prototype of the Smart Wheelchair Component System (SWCS) was developed from a laptop computer and a collection of sonar, infrared and bump sensors. The evaluation activities performed during Phase I demonstrated that the system is compatible with multiple brands of wheelchairs, can accept both continuous and switch-based input, and can support front-, mid-, and rear-wheel drive wheelchairs. During Phase II, we propose to refine the system hardware and software; replace the laptop computer with an embedded microprocessor; fabricate enclosures for the system components; and develop tools to support clinicians in installing and configuring the system. The system will be evaluated in tests involving potential users, clinicians, and wheelchair design standards. The final product will be a market-ready modular system which can be attached to a variety of standard power wheelchairs. This product has the potential to increase the independence and quality of life of many wheelchair users and potential wheelchair users whose disabilities limit their capacity for independent wheelchair navigation. [unreadable] [unreadable]